Peptide, method and composition for inhibiting melanogenesis

ABSTRACT

An isolated peptide for inhibiting melanogenesis in a mammal subject is provided. The isolated peptide consisting of an amino acid sequence of SSASTTED (SEQ ID NO: 1). Also provided are methods and compositions for inhibiting melanogenesis in a mammal subject.

FIELD OF THE INVENTION

The present invention relates generally to a peptide for inhibitingmelanogenesis or decreasing the melanin content in mammals, and methodsand compositions thereof.

BACKGROUND OF THE INVENTION

Human pigmentation results from the synthesis and distribution ofmelanin most notably in the skin and the hair. Therefore, the color ofthe skin and the hair depends principally on the types of melaninpigments present and their concentrations.

U.S. Pat. No. 6,579,848 is directed to an agouti signaling protein andpeptides as well as pharmaceutical compositions thereof and their use inmethods of inhibiting melanin production by melanocytes. U.S. Pat. No.8,669,238 discloses a method for treating hyperpigmentation comprisingadministering to a subject having hyperpigmentation, a compositioncomprising at least one inhibitor selected from the group consisting ofa kinesin Kif13A inhibitor, an inhibitor of a sub-unit of AP-1 adaptorcomplex, and an inhibitor of the interaction between a sub-unit of AP-1adaptor complex or the AP-1 adaptor complex and kinesin Kif13A. U.S.Pat. No. 8,455,023 relates to a Cinnamomum subavenium extract and itsuse in whitening cosmetology by inhibiting melanogenesis.

BRIEF SUMMARY OF THE INVENTION

It is unexpectedly found in the present invention that a peptide withthe sequence SSASTTED (SEQ ID NO: 1) is active in inhibiting ordecreasing melanogenesis in a mammal subject.

Accordingly, the present invention provides in one aspect an isolatedpeptide for inhibiting melanogenesis in a mammal subject or decreasingthe melanin content of mammalian melanocytes. The isolated peptideconsists of an amino acid sequence of SEQ ID NO: 1.

In another aspect, the present invention features a method forinhibiting melanogenesis in a mammal subject or decreasing the melanincontent of mammalian melanocytes, which comprises administering to saidsubject or said melanocytes an effective amount of an isolated peptideaccording to the present invention. In preferred embodiments of theinvention, the isolated peptide is administered topically to thesubject.

In one further aspect, the present invention provides a composition forinhibiting melanogenesis in a mammal subject or decreasing the melanincontent of mammalian melanocytes. The composition of the presentinvention may have a cosmetic use of whitening the skin of human. Thecomposition comprises an effective amount of an isolated peptideconsisting of the amino acid sequence of SEQ ID NO: 1. According tocertain embodiments of the invention, the composition may furthercomprise an acceptable carrier, and may be formulated as a topicalformulation.

It is to be understood that both the foregoing general description andthe following detailed description are exemplary and explanatory onlyand are not restrictive of the invention.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

The foregoing summary, as well as the following detailed description ofthe invention, will be better understood when read in conjunction withthe appended drawings. For the purpose of illustrating the invention,there are shown in the drawings embodiments which are presentlypreferred.

In the drawings:

FIG. 1 shows the reduced melanogenesis by the peptide of the inventionin cells. B16F10 melanoma cells were treated with 10-50 μg/ml peptide ofSEQ ID NO: 1 (“Lf H-392-399”) for 5 days with a medium change at day 3.The cells and medium were recovered in test tubes. Kojic acid is used asnegative control in the cellular study due to known inhibitory effectson tyrosinase activity. IBMX is used as positive control in the cellularstudy due to known elevator of cellular cAMP level, to inhibitmelanogenesis.

FIG. 2A shows the melanin content in cells. FIG. 2B shows the melaninsecretion in culture medium. Each measurement was made in triplicate anddata shown represent the mean±S.D.*p<0.05 compared to control.

FIG. 3 shows the tyrosinase activity decreased by the peptide of theinvention.*p<0.05 compared to control.

FIG. 4 shows the results of DOPA staining.

DETAILED DESCRIPTION OF THE INVENTION

In one aspect, the present invention features an isolated peptide forinhibiting melanogenesis in a mammal subject or decreasing the melanincontent of mammalian melanocytes, the isolated peptide consisting of anamino acid sequence of SSASTTED (SEQ ID NO: 1).

In another aspect, the invention provides a method for inhibitingmelanogenesis in a mammal subject or decreasing the melanin content ofmammalian melanocytes. The method comprises a step of administering tosaid mammal subject or said mammalian melanocytes the isolated peptideof SEQ ID NO: 1, in an amount effective to inhibit melanogenesis in themammal subject, or in an amount effective to decrease the melanincontent of said melanocytes. Preferably, the isolated peptide isadministered topically.

In yet another aspect, the present invention provides a compositioncomprising an effective amount of an isolated peptide consisting of theamino acid sequence of SEQ ID NO: 1. The composition of the presentinvention is useful in inhibiting melanogenesis or decreasing themelanin content of melanocytes in mammals. The composition may be usedfor cosmetic purposes, for example, whitening skin.

In certain embodiments of the invention, the composition furthercomprises a (physiologically) acceptable carrier.

In some preferred embodiments, the composition of the present inventionis formulated as a topical formulation.

Unless defined otherwise, all technical and scientific terms used hereinhave the same meaning as commonly understood by those of ordinary skillin the art to which this invention belongs.

The use of the word “a” or “an” when used in conjunction with the term“comprising” in the claims and/or the specification may mean “one,” butit is also consistent with the meaning of “one or more,” “at least one,”and “one or more than one.”

The term “peptide” is used herein in its conventional sense, i.e., apolymer in which the monomers are amino acids and are joined togetherthrough amide bonds, alternatively referred to as a polypeptide. Whenthe amino acids are α-amino acids, either the L-optical isomer or theD-optical isomer may be used. Additionally, unnatural amino acids, forexample, β-alanine, phenylglycine and homoarginine are also meant to beincluded. Standard abbreviations for amino acids are used.

As used herein, the term “carrier” refers to materials commonly used onthe formulation of pharmaceutical or cosmetic composition used toenhance stability, sterility and deliverability. When the peptidedelivery system is formulated as a solution or suspension, the deliverysystem is in an acceptable carrier, preferably an aqueous carrier. Avariety of aqueous carriers may be used, e.g., water, buffered water,0.8% saline, 0.3% glycine, hyaluronic acid and the like. Thecompositions may contain physiologically acceptable auxiliary substancesas required to approximate physiological conditions, such as pHadjusting and buffering agents, tonicity adjusting agents, wettingagents and the like, for example, sodium acetate, sodium lactate, sodiumchloride, potassium chloride, calcium chloride, sorbitan monolaurate,triethanolamine oleate, etc.

The term “topical” or “topically” is used herein its conventional senseas referring to a spot which can be in or on any part of the body,including but not limited to the epidermis, any other dermis, or anyother body tissue. Topical administration or application means thedirect contact of the peptide with tissue, such as skin or membranewhich contains melanin-producing cells.

The present invention contemplates the use of the isolated peptide ofSEQ ID NO: 1 as an active ingredient for various uses. In one preferredembodiment, the isolated peptide of the present invention is combinedwith an acceptable carrier to form a topical formulation which may beplaced on the skin. Topical formulations may include ointments, lotions,pastes, creams, gels, drops, suppositories, sprays, liquids, powders andtransdermal patches. Thickeners, diluents, emulsifiers, dispersing aidsor binders may be used as needed. Preferably, one function of thecarrier is to enhance skin penetration of the peptide of the presentinvention, and should be capable of delivering the peptide tomelanocytes under in vivo conditions. Suitable carriers are well knownto one of ordinary skill, and include but are not limited to water,dimethylsulfoxide, ethanol, liposomes, liquid petrolatum, petrolatumdimethylformamide, 2-pyrrolidone, oleic acid, and Azone® brandpenetration enhancer.

The present invention is further illustrated by the following examples,which are provided for the purpose of demonstration rather thanlimitation.

EXAMPLES Example 1 Peptide of SEQ ID NO: 1 Inhibits Melanogenesis inMouse Melanoma Cells

1. Materials and Methods

1.1 Preparation of Isolated Peptide of SEQ ID NO: 1

The peptide with the amino acid sequence of SSASTTED (SEQ ID NO: 1)(796.75 Da), derived from human lactoferrin, were synthesized by MDBio,Inc. (Taipei, Taiwan). The purity and composition of the peptide wereconfirmed by high performance liquid chromatography (HPLC) and massspectrometry. A 10 mg/ml sample of peptide of SEQ ID NO: 1 was producedby dissolving 10 mg of peptide powder and mixed with 1 ml doubledeionized water (ddH₂O), stored at −20° C. before use.

1.2 Cell Cultures

B16F10 murine melanoma cells were cultured in phenol red-free DMEM with10% fetal bovine serum and penicillin/streptomycin (100 IU/50 g per mL)in a humidified atmosphere containing 5% CO₂ in air at 37° C.

1.3 Melanin Content Assay

Melanin contents of cultured B16F10 cells were measured according to themethod (Lee et al., J Invest Dermatol 124, 405-411, 2005) with a slightmodification. Briefly, B16F10 cells were seeded in 6-well plate (2×10⁴cells/well) and incubated overnight to allow cells to adhere. Aftertreating with various test samples in an incubator for 5 days, washed,trypsinized and counted before pelleting. Melanin per cell wasquantified after boiling in 1 M NaOH for 1 hour and melanin content ineach sample was read from a calibration curve against syntheticeumelanin at 400 nm and converted to means±SE melanin pg/cell from 3independent experiments.

1.4 Tyrosinase Assay

Tyrosinase is the rate limiting enzyme in the melanogenic pathway. Itsmeasurement provides a highly specific and sensitive indication ofdegree of induction of melanogenesis. Tyrosinase enzyme activity ofcultured B16F10 cells were measured according to the method of (Belleiet al., J Biol Chem 285, 7288-7299, 2010) with a slight modification.Briefly, B16F10 cells were seeded in 6-well plate (2×10⁴ cells/well) andincubated overnight to allow cells to adhere. After treating withvarious test samples in an incubator for 5 days, cells were washed withPBS and then harvested using trypsin. At the end point, the cells weresolubilized with phosphate buffer (pH 6.8) containing 1% Triton X-100.The cells were then disrupted by freezing and thawing, and the lysateswere clarified by centrifugation at 10,000×g for 10 min. After proteinquantification and adjustment of protein concentrations with lysisbuffer, 100 μl of each lysate (each containing the same amount ofprotein) were aliquoted into the wells of a 96-well plate, and 100 μl of5 mM L-DOPA were then added to each well. The absorbance was measuredspectrophotometrically at 475 nm following a 30-min incubation period at37° C. The measurement was repeated three times.

1.5 DOPA Staining

DOPA staining was also performed to measure tyrosinase enzyme activity.

B16F10 cells were seeded in 6-well plate (2×10⁴ cells/well) andincubated overnight to allow cells to adhere. After treating withvarious test samples in an incubator for 4 days, cells were washed withPBS, fixation with 2% paraformaldehyde and washing with PBS a furtherthree times, the cells were incubated with 0.1% DOPA (dissolved in 0.1 MPBS) at 37° C. for 5 hour, and observed using light microscopy (Wang etal., Exp Ther Med 6, 967-972, 2013).

2. Results

2.1 Effects on Melanogenesis

Cultures of B16F10 cells treated with 50 μg/ml peptide of SEQ ID NO: 1(“Lf H-392-399”) showed reduced cell pigmentation (FIG. 1).

2.2 Effects on Melanin Contents

B16F10 cells treated with 10 and 50 μg/ml peptide of SEQ ID NO: 1 (“LfH-392-399”) showed significantly decreased melanin synthesis (FIGS. 2Aand 2B).

2.3 Effects on Tyrosinase Activity

B16F10 cells treated with 10 and 50 μg/ml peptide of SEQ ID NO: 1 (“LfH-392-399”) showed significantly decreased tyrosinase activity (FIG. 3)and the cells also showed weaker DOPA staining (FIG. 4).

It will be appreciated by those skilled in the art that changes could bemade to the embodiments described above without departing from the broadinventive concept thereof. It is understood, therefore, that thisinvention is not limited to the particular embodiments disclosed, but itis intended to cover modifications within the spirit and scope of thepresent invention as defined by the appended claims.

What is claimed is:
 1. A method for whitening skin in a human subject,which comprises administering to said subject an isolated peptideconsisting of the amino acid sequence of SEQ ID NO: 1 in an amounteffective to inhibit melanogenesis in the human subject or melanocytes.2. The method of claim 1, wherein melanin content is decreased throughthe inhibition of melanogenesis by the isolated peptide.
 3. The methodof claim 1, wherein the isolated peptide is administered to the subjecttopically.